HashiCorp does not use [semantic versioning](https://semver.org) for Vault
releases. Instead, Vault uses `X.Y.Z` notation and updates Vault as **major**
releases and **minor** patches.

- Major releases update the `Y` value
- Minor patches update the `Z` value
- On rare occasions, Enterprise-only updates use an expanded notation,
  `X.Y.Z.A`, and update the `A` value.

We strongly recommend upgrading to the latest patch for supported major releases
as soon as possible. Refer to the support article on
[support periods and end-of-life](https://support.hashicorp.com/hc/en-us/articles/360021185113-Support-Period-and-End-of-Life-EOL-Policy)
for more detail.